Loud-speaker motor



Dec. 30, 1930. R. CONOVER LOUD SPEAKER MOTOR 2 Sheets-Sheet l Filed July 16, 1928 I N VEN TOR.

A TTORNEYS Dec. 30, 1930. R. CONOVER LOUD SPEAKER MOTOR Filed July 16 1928 2 Sheets-Sheet 2 Y INVENTOR.

A TTORNEYS Patented Dec. 30, 1930 UNITED STATES PATENT OFFICE RICHARD GONOVER, OF CINCINNATI, OHIO, ASSIGNOR TO THE CROSLEY RADIO COR PORA'IION, OF CINCINNATI, OHIO, A CORPORATION OF OHIO LOUD-SPEAKER MOTOR Application filed July 16,

My invention relates to motors for loud speakers particularly to the design of the same so as to obtain a balancedanmature and reduce to a minimum all parts which will develop periods of resonance during operation of the motor that might result in a distortion of the sounds reproduced therefrom.

It is my object to provide for a structure of loud speaker motor in which accuracy of size and fitting of parts is largely eliminated, as well as rattling joints and complication of assembly. It is my object to cut down the number of different parts used in such a structure, and simplify the erection thereof.

A further one of my objects is to provide a motor which is compact and strong, and from which the motion is so directed as to permit of mounting the entire motor within the solid angle of a sound producing cone diaphragm.

These objects and other advantages to be noted I accomplish by that certain construction and arrangement of parts to be hereinafter more specifically pointed out and claimed.

In the drawings: Figure 1 is a plan view of the motor.. Figure 2 is a front elevation thereof. Figure 3 is a side elevation thereof. Figure 4 is a perspective of the magnet. Figure 5 is a perspective of one of the pole shoes.

Figure dis a plan view of one of the coil spools.

' Figure 7 is a side elevation of Figure 6.

Figure 8 is a perspective of the armature andthe restoring spring therefor.

Figuie 9 is a detail of the driving rod or 1n. P Figure 10 is a perspective of one of the pole spacers.

The motor is built upon a horseshoe shaped magnet, as a preferred form of magnet, as shown at 1, on the tips of which are mounted the pole spacers. These pieces are formed of conductive metal, preferably square rod which is cut to shape ,in a press, and having main bodies 2, and projections 3.

The spacers are mounted on the ends of the magnet by means of bolts 4 passing through during assembly.

1928. Serial No. 293,028.

The main bodies are provided with holes 5, 5, for mounting of the pole shoes on each face of the said blocks, and the projections 3, are provided with holes 6, for mounting the coil spools and the armature restoring spring. The result of the use of these spacer blocks is to apply the flux to the armature at right angles to the plane of the ends of the magnet tips, thus reducing the over all space occupied by the-motor and enabling me to mount it within the solid angle bf a conical diaphragm of normal size. j/

The pole shoes are-made of pieces of plate metal 7, with slanting'rear faces 8, all of the -1 and are held in place by the four bolts 5a,

which engage in the holes 5 in the spacer blocks.

The pole shoes are mounted in place after the rest of the motor has been assembled and mounted on the pole spacer projections.

I provide a pair of spools 9, (Figs. 6 and 7), having projections or ears 10 projecting from oneof the heads of each spool and a terminal lug 11 projectin from the'other spool head at other than right angles to the cars so that when the s 001s are assembled with the faces having-the two ears thereon in juxtaposition, the terminal lugs will not entirely overlap each other (Fig. 1).

The armature is in the form of a bar of silicon steel or other proper metal, as indicated at 12, and is held at its center or apone spool.

The second spool is then set in place over the armature spring, and then the two bolts 16 are employed to bolt the fast to the projecas has been described and the structure is completed except for attaching the wires which conduct the audio frequency current from whatever receiver is used, to the two spools. I

The armature is tipped at its ends as a result of the flux set up by the winding on the two spools, through the center of which spools the armature passes, and the restoring spring operates as a torsion spring to maintain the armature in a central position.

There is no pivotal linkage between the armature and the diaphragm, which is to be connected direct to the end of the drive rod. The parts can be rapidly and accurately assembled, and all parts are tightly bolted in place, with a minimum of bolts, and in a very compact manner.

The whole structure presents a balanced armature type of loud speaker motor, which operates very effectively with a minimum of self generated resonance.

Having thus described my invention, what I claim as new and desire to secure byLetters Patent is:

1. In a loud speaker motor, the combination of a magnet, pole spacers thereon having projections, an armature restoring spring mounted on the projections, said spring having secured thereto an armature, coils set around the armature at both sides of the restoring spring, and pole shoes mounted on thepole spacers in opposed pairs with their tips adjacent the said armature.

2. In a loud speaker motor the combination of a horse shoe magnet, blocks mounted on the sides of the tips thereof, an armature and a restoring spring therefor mounted on the blocks so that the armature extends parallel to the legs of the horseshoe magnet, coils for the armature mounted on said blocks, and pole pieces mounted on said blocks in pairs for each end of the armature.

3. In a loud speaker motor the combination with the legs of a magnet of pole spacers mounted thereon and having lateral projections, ole shoes mounted on the blocks, coil spools aving mounting ears, an armature restoring spring having mounting ears and means for securing the spools with the armature restoring spring between them, and the armature extending through the spools, by the same attaching means to the projections from the pole shoes.

4. In a loud speaker motor the combination 'with the legs of a magnet of pole spacers mounted thereon and having lateral pro c tions, pole shoes mounted on the blocks, coil spools having mounting ears, an armature restoring spring having mounting ears and means for securing the spools with the armature restoring spring between them, and the armature exten ing through the spools, by the same attaching means to the projections from the pole shoes, and pole shoes mounted on the pole spacers in pairs, one on each side of the both ends of the armature, said pole shoes being mounted on the spacer blocks.

5. In a loud speaker motor the combination with the legs of a magnet of pole spacers mounted thereon and having lateral rojections, pole shoes mounted on the bloc s, coil spools having mounting ears, an armature restoring spring having mounting ears and means for securing the spools with the armature restoring spring between them, and the armature extending through the spools, by the same attaching means to the projections from the pole shoes, and pole shoes mounted on the pole spacers in pairs, one on each side of the both ends of the armature, said pole shoes being mounted on the spacer blocks, and being formed of flat pieces, having their edges in magnetic relation to the said armature.

6. In a loud speaker motor, the combination with a magnet, pole spacers thereon, a pair of spools for armature coils, having attaching ears, and armature restoring spring with an armature extending at right angles thereto, said spring having attaching ears to match those on the coils, and common means for attaching the coils and spring to the pole spacers.

7 In a loud speaker motor, the combination,-with a magnet, pole spacers thereon, a pair of spools for armature coils, having attaching ears, and armature restoring spring with an armature extending at right angles thereto, said spring having attaching ears to match those on the coils, and common means for attaching the coils and spring to the pole spacers, said spools being alike in shape, and having the said ears on one head thereof, and terminal lugs on the other head, saidterminal lugs extending at other than right angles to the ears, whereby in the assembly the lugs will not entirely overlap eachother.

8. In a loud speaker motor, a magnet, pole spacers on the magnet, coils and an armature mounted on said pole spacers so that the axis of the coils extends parallel with the faces of the magnet on which the pole spacers are mounted, and pole shoes mounted on the side faces of the pole spacers, and a torsion spring for the armature located between the coils.

9. In a loud speaker motor, the combination with a magnet, means thereon present 1 mg a pair of supports, and a pair of coil spools having ears, together with an armature restoring spring having matching ears and located between the spools, the whole assembly held fast to said supports by common means.

10. In a loud speaker motor, the combination with a magnet, means thereon presenting a pair of supports, and a pair of coil spools having ears. together with an armature restoring spring having matching ears and located between the spools, the Whole assembly held fast to said supports by means of screws passing'through said ears, and engagmg 111 said supports;

11. In a loud speaker motor, the c'omblnation with a magnet, means thereon presenting a pair of supports, and apairof coil spools having ears, together With an armature restoring spring having matching ears and located between the spools, the Whole assembly held fast to said supports by common means, and terminal lugs located on said spools on the opposite heads thereof, to the attaching ears.

RICHARD CONOVER. 

